Ch. 8 Cell Cycle Control by pRb

Question 1

dna damage checkpoint S

Answer 1

S phase, DNA rep is halted if genome is damaged

Question 2

dna damage checkpoint G1

Answer 2

entrance into S is blocked if genome is damaged

Question 3

DNA replication not complete then…

Answer 3

entrance into M blocked

Question 4

chromatids not properly assembled on mitotic spindle…

Answer 4

entrance into anaphase blocked

Question 5

Rad 17

Answer 5

responsible for preventing re- replication of already replicated chromosomal DNA, results in increases of the ploidy of the cell

Question 6

Bulb1

Answer 6

normally prevents the separation of chromosomes in the event that one or more
chromosomal pairs are not properly aligned;

Question 7

ATR

Answer 7

responsible for halting further DNA replication until stalled replication forks are repaired

Question 8

When are cells responsive to growth factors and TGFβ?

Answer 8

During G1

Question 9

Cyclins associated with CDKs activate…

Answer 9

the catalytic activity of their CDK partners

Question 10

Cells are no longer responsive to growth factors or TGFβ after passing the…

Answer 10

restriction point

Question 11

B-type cyclins increase in

Answer 11

anticipation of mitosis

Question 12

at the end of mitosis cyclin B levels are

Answer 12

dramatically decreased

Question 13

D-type cyclins are controlled by

Answer 13

extracellular signals (mitogenic growth factors)

Question 14

how does removal of growth factor affect cyclin D1

Answer 14

rapid decrease in D1 levels

Question 15

P21Cip1, p27Kip1 inhibit

Answer 15

Cyclin CDKs

Question 16

When TGF-β is applied to epithelial cells, it triggers downstream responses that

Answer 16

antagonize cell proliferation

Question 17

P21Cip1 levels are increased in response to

Answer 17

dna damage

Question 18

In low grade, less advanced human mammary carcinomas, levels of activated Akt/PKB

Answer 18

are low and and p27Kip1 is able to carry out its anti-proliferative function in the nucleus

Question 19

In high grade tumors, activated Akt/PKB levels are

Answer 19

high and p27Kip1 is now found in the cytoplasm and, therefore, cannot inhibit cyclin-CDK complexes

Question 20

pRb is unphosphorylated in

Answer 20

G0

Question 21

pRb weakly phosphorylated in

Answer 21

G1 = growth inhibitory

Question 22

If cell experiences serious physiologic stress while in S phase or G2

Answer 22

pRB phosphorylation can be reversed

Question 23

pRB

Answer 23

guardian of restriction point gate

Question 24

What is amplified in about 1/3 of HNSCC tumors

Answer 24

CD1